Big Sur - will not boot with Thunderbolt monitor connected

MBR 2013 ( later Ver. ) 27 in Thunderbolt Display

Same issue. I noticed while attempting to power on while connected the M2 charging end and the mbp was getting hot.Did not roll back , just power up disconnected and then connect and all is cool.

Efectivamente, después de actualizar a la 11.1 de Big Sur sigue el mismo problema en Imac 27" finales 2015. El monitor Thunderbolt impide que el ordenador salga del modo en reposo y produce Panic Kermel. Sin el monitor conectado funciona perfectamente. En Catalina nunca pasaba.

Esperemos una solución pronto, es bastante desesperante tener el ordenador siempre en funcionamiento evitando modo reposo, en cuanto energía como a desgaste del ordenador.

Worked for me too (I left the Thunderbolt Display connected) and the 11.1 update took a while tbh (it seemed to be ‘stuck’ on 2 minutes remaining) I left it alone however and came back after 30 minutes...

All working (and restarting) fine now - as it used to do! including the Thunderbolt monitor camera (and speakers) 👍

If they have already downgraded to Catalina they only need to update to Catalina 10.15.7 released at the same time as Big Sur 11.1 and the issue is resolved. There is no need to upgrade to Big Sur to get the firmware fix.

Mine is fixed after doing the Catalina security update. Thunderbolt now works going direct to Bootcamp or MacOS.

Security update 2020-001 10.15.7

i installed that on my MacBook last night and my Thunderbolt Display is working again.

Then if you can go back to Catalina and install 10.15.7 check it works then upgrade to big sur again.

Same issue too (I need to disconnect and reconnect my thunderbolt monitor to enable me to restart)?

All I get is the start-up chimes twice and then absolutley nothing??

Let's hope Apple can roll out a fix (soon) asap - please?

I have the same problem. Macbook Air 2014, Big Sur will not boot if Thunderbolt display connected. Disconnect it, macbook air boots up fine. Then connect thunderbolt display, and that works correctly. Macbook simply will not boot, or restart/boot if the thunderbolt display is connected.

I have the same problem. I just get a blank (blackish but backlit) screen. I must disconnect my Thunderbolt Display when I restart. I verified this by restarting my Thunderbolt Display connected (blank screen each time) and disconnected (successfully restarted) from my MacBook.

MacBook Pro (Retina, 15-inch, Late 2013). 27" Thunderbolt monitor.

Thank you for sharing Howard - please do update your post when/if Apple identify and (hopefully contact you) with a timeframe for implementing the necessary patch?

PS very disappointing (and surprising) tbh this was not identified and properly addressed during their beta testing program....

MacBook Pro (13-inch, 2016, Four Thunderbolt 3 Ports) with Thunderbolt screen - exactly the same issues for me, have sent a bug report. Its a disgrace that they released the OS with this level of reduced functionality when there are hundreds if not thousands of Thunderbolt screen users out there. I can take a few minor bugs occurring on an upgrade but this is horrendous.

I have also had Time Machine issues backing up to a Synology NAS drive since going to Big Sur which has pushed me to third party back up software which is a cost but the more I move away from Apple designed software the happier I am.

I don't think Apple are concerned with Intel based MacBook users any more - their strategy seems to be to force us all to upgrade and pay out for the new books with Apple M1 chip. Call me cynical but I am not holding my breath for a Thunderbolt fix...

Extra info to what I posted above. My 2016 MacBook on Big Sur will boot with thunderbolt screen - just constantly crashes and loses blue tooth magic mouse , camera and speaker connections.

Boots fine without thunderbolt connection and seems to work with camera and Bluetooth functions.

Bravo Wall-O-Sound! I am so frustrated by big corporations telling us what is and what is not 'the problem.' You are right on about the Thunderbolt Monitor presence as a periphial causing the boot up problem. I am still waiting for Apple to address this too.

I have a mid 2015 MBP 15" with 2 daisy chained Thunderbolt displays. Everything was working well until I had to finally unplug my laptop for a trip. Upon returning and reconnecting, I realized that the cameras AND the audio on the Thunderbolt displays are NO LONGER DETECTED. When I use Zoom or FaceTime without the laptop screen open, the system doesn't see a camera and Zoom crashes and so does FaceTime. PhotoBooth also says no cameras detected. When I open the laptop up, it detects ONLY the speaker and camera on the MacBook Pro itself and will allow me to use Zoom or FaceTime or Photo Booth, but it STILL won't detect camera or built in speakers on the Thunderbolt Displays. Any thoughts on this???

Thanks!